Nowadays, the development of display devices is getting faster and faster. With the rise of touch-screen mobile phones, the use of narrow bezels in the mobile phones has become a trend because the use of a narrow bezel makes a front face of the phone more compact. However, in the existing narrow-bezel mobile phones, only bezels on both sides of the mobile phone are narrowed, and it is difficult for upper and lower bezels to realize a narrow bezel design because they accommodate electronic components. For example, for a lower bezel portion provided with a home button, since a light bar, a microphone, and other components are usually mounted in the bezel, a narrow bezel design can hardly be achieved.